Hydraulic compacting press



June 29, 1965 J. HALLER 3,191,232

HYDRAULIC COMPACTING PRESS Filed Dec. 7. 1961 4 Sheets-Sheet l FIG.|

INVENTOR. JOHN HALLER' /o mm V ATTORNEYS,

June 29, 1965 J. HALLER HYDRAULIC COMPACTING PRESS 4 Sheets-Sheet 2 Filed Dec. 7, 1961 FIG-2 zm i 2/ I FIG-4 INVENTOR. JOHN HALLER.

away (7 ATTORNEYS- June 29, 1965 J. HALLER 3,191,232

HYDRAULIC COMPAGTING PRESS Filed D80. 7, 1961 4 Sheets-Sheet 3 [T32 I: a! w FIG 5 lu m-ua I82 104 INVENTOR.

JOHN HALLER.

ATTORNEYS June 29, 1965 J. HAl-LER HYDRAULIC COMPAGTING PRESS 4 Sheets-Sheer; 4

Filed Dec. 7, 1961 m mm 5 mm a 1A an H m M \M O J l m m an Nw mm UVN m3 wQE V 3,191,232 HYDRAULIC COMPACTING PRESS .Iohn Heller, 1850i) Sheldon Road, Northville, Mich. Filed Dec. 7, 1961, Ser. No. 157,780 4 Uiaims. (Cl. 1816.7)

This invention relates to hydraulic presses, and, in particular, to hydraulic compacting presses for producing shouldered or flanged workpieces from powdered materials either metallic or non-metallic.

Hitherto, it has been very difi'icult to produce shouldered or flanged workpieces from sintered powdered metal or non-metallic materials such as sintered powdered nylon plastic, for the reason that during ejection of the workpiece, the slightest departure from a common speed for all the moving parts caused a crack to develop between the thick and thin portions of the workpiece. Such workpieces in which this problem arises include thin discs with central hubs or with thickened marginal flanges, thin gears, sprockets or cams with axially thicker hubs, and other workpieces having sudden and considerable differences in thickness existing between adjacent portions thereof. The present invention provides a hydraulic compacting press which insures even and uniform motion of the various parts in a predetermined sequence whereby ejection of the finished flanged workpiece is carried out by successively accomplished reverse stripping without the occurrence of such breakage.

Accordingly, one object of the present invention is to provide a hydraulic compacting press for producing compacts or briquettes of powdered metal or non-metallic powdered materials which are to be subsequently sintered, which have axially thin portions bordering upon axially thick portions, such as, for example, an axially thin disc having an axially-thick hub, wherein ejection is effected by moving the die and shoulder punch relatively to the core rod in an even and uniform manner to accomplish reverse stripping.

Another object is to provide a hydraulic compacting press, as set forth in the object immediately preceding, wherein ejection of the flanged workpiece is accomplished sequentially, the die being first withdrawn downward from the side surface of the flange so as to release lateral pressure on the flange while the shoulder punch or tubular plunger is maintained temporarily stationary relatively to the lower punch which supports the bottom of the workpiece, after which the tubular punch or plunger is retracted downwardly to leave the entire workpiece exposed for expulsion by the lateral motion of the filling box or shoe.

Another object is to provide a hydraulic compacting press of the foregoing character wherein the die table is adapted to be supported upon hydraulic cushioning cylinders which can be temporarily locked in immovable positions by mechanically-actuated positive locking devices, which can thereafter be released to permit hydraulic cushioning and pressure-responsive yielding henceforth to take place.

Another object is to provide a hydraulic compacting press of the foregoing character wherein the core rod which supports the central hub or axially-thicker portion of the workpiece is fixedly and immovably mounted upon the press frame or other stationary supporting structure so as to be substantially as unyielding as an anvil during the operation of the press.

Other objects and advantages of the invention will become apparent during the course of the following description of the accompanying drawings, wherein:

FIGURE 1 is a diagrammatic front elevation, mainly in central vertical section, of a hydraulic compacting press for producing flanged workpieces, according to one form United States Patent stanzas Ice of the invention, showing the relative positions of the moving parts at the conclusion of one pressing operation, ready for expulsion of the workpiece after ejection, and ready for the start of a new filling and pressing cycle and with the secondary die table supporting plungers in their mechanically-unlockecl positions;

FIGURE 2 is a fragmentary vertical section taken along the line 22 in FIGURE 1, showing the feed box of powdered material in its retracted position ready to move forward and expel the ejected workpiece and position the feed box for subsequent filling of the die cavity with powdered material;

FIGURE 3 is a view similar to FIGURE 2 but showing the feed box moved to its advanced position over the die after having expelled the previously formed workpiece;

FIGURE 4 is a view similar to FIGURES 2 and 3, showing the formation of the die cavity and its simultaneous filling with powdered material in response to the upward motion of the main and secondary die tables and the die and shoulder punch carried by them;

FIGURE 5 is a view similar to FIGURE 1, but showing the relative positions of the parts of the press with the die cavity fiiled and the feed box retracted from the position shown in FIGURE 4, and with the secondary die table supporting plungers in their mechanically locked positions;

FIGURE 6 is a diagrammatic horizontal section taken along the line s e in FIGURE 1, showing the mechanical locking device for the secondary die table supporting plungers in their mechanically unlocked positions;

FIGURE 7 is a view similar to FIGURE 6, but with the supporting plungers shown in their mechanically locked positions;

FIGURE 8 is a fragmentary central vertical section, partly in front elevation, of the central portion of the press with the moving parts in the positions immediately following their positions of FIGURE 5, with pressing of the die cavity charge of powdered material having just terminated; and

FIGURE 9 is a view similar to FIGURE 8, but showing the upper pressing ram and the upper punch being retracted and the secondary die table moving upward to eject the compacted workpiece to the position of FIG URE 1.

Referring to the drawings in detail, FIGURE 1 shows diagrammatically a hydraulic compacting press, generally designated 20, according to one form of the invention, in the relative positions of the various moving parts at the end of one operating cycle which has produced a finished compact or briquette ready to be expelled, and therefore also at the beginning of the next operating cycle wherein the feed box or filling shoe expels the previously made compact or briquette W immediately prior to moving over the die set to till the die cavity with powdered material for producing the next workpiece. The workpiece W consists of a central hub H of considerably greator thickness than the annular flange F which surrounds its upper portion. The press 2d of the present invention prevents cracks or other evidence or results of breakage from occurring at the junction I between the flange F and core H of the workpiece W, in the manner and by reason of the construction explained below.

The press 20 is provided with a press frame, generally designated 22, consisting of a rectangular press bed 24 adapted to rest upon the door or upon a concrete foundation (not shown), and having longitudinal frame members or strain rods 26 rising from the four corners of the bed 24 and terminating at their upper ends in a press head 28. Ordinarily, the strain rods 2-6 are provided with reduced diameter threaded portions at their upper and lower ends and pass through holes in the press bed 24 and press head 28, beyond which they are provided with threaded retaining nuts (not shown) by which the bed 24 and head 28 are held in assembly with the strain rods 26; The construct-ion has been shown as simplified and diagrammatic in the present drawings inorderto clarify the disclosure;

ing circuit including a driving motor, hydraulicpump, hydraulic flu-id reservoir for the working fluid, generally oil, and the necessary valves, electrical control devices and other componentsconventionally presentin such cir- The press head 28 normally'serves as a platform to support the hydraulic pressure fluid operat-r slides relatively thereto vertically in the die bore 64. The tubular shoulderipunch 80 in turn contains a bore 82 which slid-ably receives a tubular lower or bottom punch 84 also coaxial with the main press axis X- X and containing a central bore 86and having an annular top surface 88. Mounted in the central bore 86-for sliding motion relatively thereto is acore rod 90 having .a top surface 92 The tubular bottom punch 84 is stationary throughout all of the operationsz'of the press 29, and rests upon the upper end of a pedestal or pillar 94, which in 7 turn rests upon the stationary'press bed 24.

cuits. The hydraulic pressure fluid operatingcircuit and these components are familiar to hydraulic engineers and are available upon'the open market, hence these components, ap-artv from the hydraulic devices shown inthe drawings, are beyond the scope'of the present invention.

' 'The strain rods 26 intermediate their opposite ends are provided vwith intermediate threaded portions 30 (FIG- URE 1) carrying upper and lower threaded stop collars or nuts 32 and 34 respectively. Secured to and depending from the, press head 28'are auxiliary cylinders 36 spaced laterally away from the center line or main axis 'X X ofthe press 20 and having cylinder bores orchamv core 111C199; the outer. ends of the bar. 98 are bored as at bers37 containing the piston heads .378 of auxiliary plung er s 40. The cylinders '36 are provided with upper and lower service ports 42 and 44 to which pipes 46 and 48 are connected respectively.- The pipes 46 and 48 are connected tothe hydraulic circuit (not shown) located mainly on top otthe press head 28, by way of ;a conventional four-way valve (not shown) .by which hydraulic pressure fluid-is simultaneously supplied to oneot the service pipes 46 and its port -42 While beingwithdrawn from the other service pipe 48:and service port 44 and vice versa, as explained below in connection with the operation of the invention. The assembly of the auxiliary hydraulic cylinders'3.6,,their, piston heads 38 ,andplungers deforms auxiliary hydraulic reciprocatory motors,v generally designated 50. V

.The lower ends of the auxiliary hydraulic plungers 40 are threaded as at 5-2 into a generally horizontal rectangu-r lar main diej'table 54 (FIGURE l which is provided at its four corners with smooth bores 56 to receive and slid-ably engage the threaded portions 30 of the strain rods 26 between the upper and lower stop collars or nuts 32 and 3,4. The main die'table 54 is also provided witha steppedcentral vertical bore 58 containing the correspondingly flanged tubular die 60 f a compacting die set, generally designated 62. The tubular die 60 is fixed- 1y mounted in the bore 58 against relative motion and contains a bore 64 constituting the outer bore of the die cavity, generally designated 66 (FIGURE formed by the die set 62 during the pressing step of the press 20.

Threaded as at 68 into the lower side of the main die table 54 at laterally-spaced locations rela-tivelyrto the main center line or axis XX of the press are the upper ends of secondary die table suspension rods 78) (FIGURE 1) the lower ends of which are also threaded to receive secondary die table carrier nuts 72. Mounted on the upper'portions of the secondary die table suspension rods 70 adjacent the main die table 54 are compression springs 74, thevlower ends of which engage-the top of a rectangular secondary die table -76 which has bores 78 therethrough at its four corners. The bores 78 loosely and sl-idably engage the suspension rods 70 so that thelsecondary die table 76 can rise and-fall relatively to the main die table 54 in guided relationship therewith while suspended at least part of the time therefrom The compressionsprings 74 urge the secondary die table 76 downward toward the secondary die table carrier nuts 72,

the downward motion of the secondary die -t-ab1e-76,however, .being resisted by other components describedbel-ow.

Mounted upon the central portion of the secondarydie table coaxial with the main axis XX of the press 20 (FIGURE 1), is a tubular shoulder punch or flange punch,'80 which telescopes with the tubular die 60 and 102 to receive the threaded lower endslof bar suspension rods 104 carrying middle and lower retaining nuts 106 and 108 engaging the upper and lower sides of the bar98. The suspensi-odrods 10,4 pass loosely through vertical ,bores' 110 in the secondary die table 76 and are threaded at their upper ends into laterally-spaced threaded sockets in on-theglower side of the main die table 5,4 and held in place by lock nut-r114. The secondary die table '76 contains an enlarged bore 116) through'which the bottom punch passes to permit relative rise and fall of the secondary die table '76,' a I v The secondary die table 76 between the bores. 78 ,and 110 (FIGURE '1) is provided with laterally-spaced threaded bores 118 threadedly receiving correspondingly- .threaded flanges or headed stop bushings or shoulder ejection adjustment bushings 1'20 havingstop heads 122 and central guide pin bores 12 4. Slidably mounted in the guide pin bores 124 are headed guide pins 126, the

stop heads 12 8 of which are secured to the lower side of the main die table 54. The shank'of each guide pin 1 26 passes through thebore 124 initsrespective stop bushing ,1' 20 into'the central bore J30 of a *headed'main die table float adjustment bushing or lower stop bushing 132 (FIGURE 5 which *hasaetop head lfi tand in turn is threaded-into a correspondingly threadqi bore 136 in a cushioning plunger 138 forming the moving part of a hydraulic cushioning motor, generally designated 140, of which thereare two,each having a cylinder 142c'on- .taining a cylinderbore 144 within which ,is reciprocably mounted the piston head 146 of the cushioning plunger 1138, the stem or piston rod-148 of which passes slidably through a bore 15 .0 coaxial with the cylinder boref144.

Each cylinder 142. above the bore 150 (FIGURE 1) .is provided with an enlarged bore 152 above which is a counterbore154, above which in turn is a continuation portion 156 of theborelSO: The stem or'pi ston rod 148 'tween:the outwardly-projecting stop lugs 158 in the uplocked (FIGURE positions, so as to permit vertical motion of the cushioning plungers 138. The inwardly- .projecting locking or stoplugs 164 are separated from one another by radial grooves 16.8 in which the outwardlyprojecting stop lugs 158' in the cushioning plungers 1338 slide vertically inthe unlocked position of thelocking device 160v (FIGURE; 6). Theinwardly-projecting stop 55 lugs 164 on the annular geared stop collars 162 are located on a lower level than the plunger rod stop lugs 158 in the raised and locked position of the cushioning plungers 138 (FIGURE so that upon rotation of the geared stop collars 162, the inwardly projecting segmental stops 16-! thereof pass beneath the outwardly-projecting segmental stop lugs 1558 on the plunger rods 151' so as to temporarily prevent downward motion of the cushioning plungers 138.

Meshing with the gear teeth 166 on the geared stop collars 162 (FIGURE 6) are rack teeth 170 on spaced aligned rack bars or racks 172 (FIGURES 6 and 7) which in turn are interconnected by a U-shaped bridge member 174 to form a dual rack assembly, generally designated 176. One of the racks 172 is bored and threaded at its outer end as at 178 for connection to a reciprocatory hydraulic operating motor, generally designated 13%. The latter consists of a hydraulic cylinder 182 containing a cylinder bore 184 in which the head 186 of an operating piston 138 is reciprocably mounted and which has a piston rod 1% threaded into the threaded bore 178 in the rack bar 172. The operating cylinder or locking cylinder 182 is provided with service ports 192 and 194 (FIGURES 6 and 7) to which are connected service pipes 196 and 198 respectively connected in turn to the hydraulic circuit located on the press head 23 (FIGURE 1) and reciprocated thereby to lock or unlock the locking devices 169, as explained below in connection with the operation of the invention.

Mounted on the main die table 54 and movable upward and downward therewith as a unit is a powdered material filling and workpiece ejecting device, generally designated 2% (FIGURE 2) located on the top surface 262 of the main die table 54- and at the rear of the die cavity 66. The filling and ejection device 2% includes a feed box or feed shoe 294 in the form of an inclined hopper with an upright receiving portion 266 and an inclined feeding portion 268 with an outlet 210 at the bottom thereof. Mounted on the forward end of the feed box or feed shoe 264 is an expulsion box or shoe 2% to encounter and expel the finished compacted workpiece W upon completion of the pressing cycle.

The feed box or feed shoe 204 (FIGURE 2) is reciprocably mounted on the top surface 2ii2 of the main die table 54 and is provided with a rearwardly-projecting coupling boss 214 (FIGURE 2) which is bored and threaded as at 216 to receive the threaded forward end of the piston 218 of a feed operating reciprocatory hydraulic motor, generally designated 220. The motor 220 includes a hydraulic cylinder 222 provided with a cylinder bore 224 within which the piston head 226 of the piston 213 is reciprocable, the piston rod 228 thereof being threaded at 216 into the coupling boss 214. Service ports 235i and 232 at the opposite ends of the cylinder 222 are connected to pressure fluid supply pipes 234 and 2236 respectively for supplying pressure fluid to the opposite ends of the cylinder 222 in order to reciprocate the piston 218 and consequently move the feed box or feed shoe 2% back and forth over the top surface 202 of the main die table 54 to positions in line with and out of line with the die cavity 66.

Pressing of the charge of powdered material within the compacting die set 62 is accomplished by a stepped upper punch, generally designated 240 (FIGURE 1), which, as its name suggests, consists of a reduced diameter lower portion 242 adapted to telescope with the bore 64 within the tubular lower die 66 (FIGURE 9) and an enlargeddiameter upper or base portion 244 which is attached in any suitable manner to a vertically-reciprocable main pressing ram or platen 246. The ram or platen 246 is bored and threaded as at 248 coaxial with the central axis XX of the press 20' to receive the correspondinglythreaded reduced diameter lower end of the piston rod 259 having a piston head 252 constituting the main pressing plunger 254 reciprocably mounted in the bore 256 of a main hydraulic cylinder 28 of the main reciprocatory hydraulic pressing motor, generally designated 260. The hydraulic motor 260 is likewise double-acting having upper and lower service parts 262 and 264 to which are connected service pipes (not shown) leading to the hydraulic pressure fluid supply circuit mounted on the press head 23.

The piston rod 256 of the main pressing ram 254 is provided with an intermediate diameter portion 251 adjacent the head 252 and connected to a reduced diameter lower portion 253 at an annular shoulder 255. The lower end of the cylinder bore 25% is closed by an annular closure gland 257 held in place by a main pressing cylinder extension head or stop bracket 259 bolted thereto and containing a reduced diameter threaded bore 261 engaged by a correspondingly-threaded stop ring or bushing 263 loosely and relatively rotatably surrounding the reduced diameter lower portion 253 of the piston rod 250. The stop bushing 263 is provided at its upper end with wrench and spanner recesses 265, access to which is gained through an access opening 287 in the extension head or stop bracket 259. By rotating the stop bushing 263 by means of a suitable wrench engaging the recesses 265 through the access opening 267, the stop bushing 263 is moved upward or downward to change the halting location of the main ram 254 and consequently to predetermine the depth to which the reduced diameter lower portion 242 of the upper punch 240 will enter the bore 64 in the tubular lower die 6i). This in turn regulates the thickness of the flange F or" the workpiece W.

The main pressing ram 246 near its opposite ends is also bored and threaded to provide sockets 266 which threadedly receive the correspondingly-threaded reduced diameter lower ends of piston rods 268 terminating in their upper ends in piston heads 2'70 and collectively forming secondary upper plungers 272. The piston heads 27% are reciprocable in cylinder bores 274 formed in hydraulic cylinders 276 and collectively forming secondary upper hydraulic motors, generally designated 280, Each of the secondary reciprocatory hydraulic motors 28th is provided with upper and lower service ports 282 and 284 respectively which are likewise connected to the hy draulic pressure fluid supply circuit mounted on the press head 28 by pipes (not shown).

Operation- In the operation of the hydraulic compacting press 20, let it be assumed that the press 20 is at the end of a pressing cycle with the moving parts in their relative positions shown in FIGURE 1 and with the flanged workpiece W ejected from the die set 62 but not yet expelled from the main die table 54. This terminating position of one cycle of operations is thus the starting position of the next cycle of operations wherein the pressing ram 246 and upper punch 240 are retracted into their raised or up position (FIGURE 1), and the powdered material feed boX or feed shoe 2694 of the powdered material filling and workpiece ejecting device 264) is retracted to its rearward position (FIGURE 2). The main die table 54 is in its lowered position against the die table lower stop nut 34 and the secondary die table 76 is held down by the main die table 54 through the agency of the stop heads 128 engaging the upper ends of the threaded ejection adjustment bushings (FIGURE 1).

In the starting position of the press 2f), the geared annular stop collars 162 are in their unlocked positions (FIGURE 6). The cushioning plungers 133 carrying the locking lugs 158 are urged upwardly by hydraulic pressure fluid standing in the portions of the cylinder bores I44 beneath the piston heads 146, but are held down because of the greater weight of the main die table 54 and its associated parts pressing downward upon the threaded bushings 120 which have heads 122 engaging heads 134 on lower stop bushings 132 threaded into the upper ends of the cushioning plungers 138.

Assuming that the operator has filled the feed box or feed shoe 204 with a charge of suitable powdered material, such as powdered iron, powdered bronze or alloys thereof, or suitable powdered non-metallic materials, such as the polyamide plastic commercially known as nylon, the operator starts the hydraulic. system in operation to cause the automatic pressing cycle. to'commence.

the piston 218 of the hydraulic motor 220 to advance to the left upon its forward stroke, carrying with it the feed box 204 and the workpiece expulsion abutment 212. When the latter encounters the flanged workpiece W resting'upon the top surface 88 of the bottom punch'84, it

expels the workpiece W, as shown in FIGURE 3, while it moves into its filling position with its'outlet 210 over the .die cavity 66. The thus-expelled finished workpiece When this occurs (FIGURE 2), hydraulic pressure fluid passes through the service pipe 234 into the rearward end of the hydraulic feed cylinder 222, causing W falls oh the main die table 54 into a collection box I (not shown). v

Hydraulic pressure fluid is now directed into the pipes 48 leading to the ports 44 beneath the piston heads'38- of the auxiliary plungers 40 (FIGURE 1), causing the latter and the main die table 54 to move upward, carrying with it the tubular outer die 62 and the core rod 90 engages the charge or ill in the die cavity 66, and continues downward into the die cavity 66 (FIGURE 8). As the upper punch 240 moves downward into the die cavity 66, compressing the powdered material charge therein, the pressuretransmitted therethrough to the main ,die table 54 forces the secondary die table 76 and the tubular flange or shoulder punch 80 carried thereby to float downward with the pressingram 246, as the immovable bottom punch-84. takes the thrust of the bottom of the charge. 7 7

,Meanwhile, the downwardmotion of the secondary die table 76, brought about by'the thrust of the upper punch 240 upon the powdered materialcharge in the die through the raising of the member 98 by the rods l04,

until the main die table 54 encounters the upper die table stops 32 on the strain rods 26, halting the die table 54 (FIGURE 5). The upward motion of the main die table 54 carries with it the secondary die table 76 when the die-table-carried nuts 72 on the suspension rods 70 thereof encounter the die table 76. The foregoing actions have now caused the moving parts to assume the ary die table 76 has caused the tubular flange punch or.

shoulder'80 to'rise relatively to the stationary lower, or bottom punch "84 so as to expose the entire die cavity 66 (FIGURE 5). When this occurs, the powdered material within the feed box or feed shoe 204 (FIGURE 4) fallstthrough the outlet 210 thereof into the die cavity 66 and fillstit, as shown in FIGURE 5.

With the downward pressure from the weight of the main and secondary die tables 54 and 76 thus removed by the rising thereof, the cushioning ,plungers 138 of the reciprocatory hydraulic cushioning motors 140 are forced upward by the pressure of the hydraulic pressure fluid in their cylinder bores 144 beneath their piston heads 146, causing their radially-projecting locking lugs 158 to rise through the slots or grooves 168 between the cavity 66(FIGURE 8) pulls the main die table 54 downward with it by itsengagement with the stop or carrier nuts 72 upon thelower ends of the rods 70. It'Will be recalled that hydraulic pressure fluid was previouslysupplied to the lower ends of the die table cylinders 36 of the reciprocatory motors to raise the main die table 54 into engagement with the upper strain rod stops 32,

"and this pressure still acts as a counter pressure to resist the downward floating of the main and secondary inwardly-projecting locking or stop lugs' 164 (FIGURE 5), coming to a halt 'againstjthe upper ends of thecylinders 142, thereby attaining their raised positions wherein they can be lockedj t p 7 v Hydraulic pressure fluid is now supplied to the service pipe 196 (FIGURE 6). and port 122 at the forward end of the cylinder '182 of the reciprocatory hydraulic locking motor 180, urging the piston head 186 and piston rod 190 to the, right (FIGURE 7), carrying with it the. rack bars 172 and consequently rotating the geared annular stop collars162 in a clockwise direction so as to move the inwardly-projecting stop lugs 164 thereof beneath the outwardlyeprojecting stop lugs 1640f the cushioning plungers 138, locking the, latter positively and mechanically in their raised positions (FIGURES 5 and 7). I I I Hydraulic pressure fluid is now supplied to the pipe 236 and port 232 (FIGURE 4 of thejfeed box shifting hydraulic motor 220, shifting or retracting the feed box 204 from its forward or filling position of FIGURE 4 to its rearward or retracted position of FIGURE 2. As' the feed box 204 thus moves rearwardly, it wipes the surplus powdered material off the top of the die cavity die tables 54' and 76.

As the main pressin'g ram 246 and upper punch 240 contin'ueto move downward, the 'stop bushings 122 (FIGUREv 8) engage-the stop bushings 132 on the upper ends of the piston 'rods 148 of the cushioning plungers 138, halting the downward travel of the secondary die table 76 because the plungers'138are still solidly locked to the cylinders 142 resting upon the press bed 24 against downward travel by the interengagement of their locking lugs 158 and the stop lugs 164 beneath them (FIGURES 7 and 8). The main pressing ram 246 and upperpunch 240 however continue to move downward to predeter mined positions against a preset stop bushing 263. (FIG- URE 8).. The workpiece W is now completely formed and finish-compacted (t0 the 1 desired predetermined density. I V I Pressure fluid'is now supplied to the ports 264 and 284 atthe lower ends of the main. and secondary hydraulic cylinders 258 and 276 (FIGURE 8), causing the main and secondary plungers 254 and 40 to be retracted upward (FIGURE'9), carrying withthern the main pressing ram "246 andupper punch 240, removing the downward pressure previously exerted bythem upon the main and secondary diertables 54 and 76. Hydraulic pressure fluid is now supplied to" the service pipe 198 and port 194 at the rearward endof the lock-operating cylinder 1 82 of; the lockoperating motor (FIG- URE 7 causing the plunger 188 thereof to move to the left"(FIGURE 6), consequentlyrotating the geared stop collars 162 so that their inwardly-projectinglugs 164 move counterclockwise from beneath the outwardlyprojecting lugs 158 on the piston rods 148 of the cushioning plungers 138. With the cushioning plungers 138 thus unlocked and free to move downward, they are nevertheless held up to "exert a back-up pressure by hydraulic pressure fluid in the lowerends of the cylinder bores 144 ofthe cylinders 142 of, the reciprocatory cushioning motors 140. This back-up? hydraulic fluid is retained within the cushioning cylinders 142 by a pressure reliefvalve in the hydraulic circuit (not shown) which has a releasepressure set above the pressure req ired to strip the flange F of the workpiece'W from 9 the side wall of the bore 64 within the tubular die 62, as explained below.

While the plungers 138 of the cushioning motors 140 are held up in this manner through the hydraulic backup fluid within the lower ends of the cushioning cylinders 142, the engagement of the stop bushings 122 of the secondary die table 76 with the stop bushings 132 on the upper ends of the cushioning plungers 138 prevent the secondary die table 76 and the flange or shoulder punch 80 temporarily from descending (FIGURE 9). Hydraulic pressure fluid is now supplied to the service pipe 46 and port 42 at the upper ends of the die table cylinders 36 of the reciprocatory die motors 50, cansing the main die table 54 and die 60 to move downward in telescoping relationship to the shoulder or flange punch 80, exposing and thereby ejecting the flange F of the workpiece W from the die cavity 66 of the die set 62 while at the same time, by this reverse stripping, the core rod 90 has been carried downward through its connection by the bar 98 and suspension rod 104 to strip the bore B in the workpiece W from the core rod 90 (FIGURE 9).

By reason of the guide pin stops or heads 128 with the bushings 120 threaded into the secondary die table 76 (FIGURE 9) and the engagement of the heads 122 on the lower ends of the bushings 120 with the heads 134 on the upper ends of the stops 132, the above-named stops transmit the downward thrust of the die table plungers 40 and main secondary die tables 54 and 76 through the hydraulic cushioning plungers 138 to the hydraulic fluid in the lower ends of the cylinder bores 144 of the hydraulic cushioning cylinders 142. This action overcomes the set pressure of the relief valve (not shown) connected thereto so as to release back-up hydraulic fluid from the lower ends of the hydraulic cushioning cylinders 142 (FIGURE 9), permitting the main and secondary die tables 54 and 76 to continue to move downward from the position of FIGURE 9 wherein only the flange F or upper portion of the workpiece has been ejected or stripped to the FIGURE 1 position where the shoulder or flange punch 80 carried by the secondary die table 76 has telescoped downward relatively to the bottom punch 84. The latter it will be recalled, has been held immovable upon the pedestal 94 rising from and resting upon the press bed 24. This action strips or ejects the hub portion H of the flanged workpiece W (FIGURE 1), exposing the entire workpiece W.

The above-described sequential reverse stripping action completes the operating cycle of the press. The electrohydraulic system or circuit of the press then automatically starts a new operating cycle, repeating the foregoing sequence of operations commencing with the forward motion of the feed box 204 from its retracted position of FIGURE 2 to its advanced position of FIGURE 3, expelling the thus-ejected workpiece W into the collection box (not shown), as shown in FIGURE 3, and positioning the feed box 204 ready to fill the die cavity 66 as soon as it is again formed by the upward motion of the main and secondary die tables 54 and 76 from their positions of FIGURE 1 to their positions of FIGURE 5, as described above.

What I claim is:

1. A hydraulic compacting press for producing flanged workpieces, comprising a press frame,

a main die table mounted for reciprocation on said press frame, a tubular die mounted on said main die table,

a secondary die table connected to said main die table for reciprocation relatively thereto, a tubular flange punch mounted on said secondary die table in telescoping relationship with the tubular die,

a bottom punch support mounted on said press frame,

a bottom punch mounted on said bottom punch support in telescoping relationship with the flange punch,

a hydraulic main die table reciprocatory motor operatively connected to said main die table,

a main pressing platen mounted for reciprocation on said press frame above said main die table, a main pressing punch mounted on said main pressing platen,

a main hydraulic reciprocatory pressing motor operatively connected to said platen,

a hydraulic reciprocatory cushioning motor disposed adjacent said secondary die table and having a reciprocable cushioning plunger yieldingly engageable thereby in response to motion of said secondary die table toward said cushioning motor during the compacting stroke of said main pressing platen,

and a movable locking device anchored to said press frame and movable into and out of locking engagement with said cushioning plunger into and out of immobilizing relationship therewith.

2. A hydraulic compacting press, according to claim 1, wherein axially adjustable coacting stops are disposed between said plunger of said cushioning motor and said secondary die table.

3. A hydraulic compacting press, according to claim 1, wherein means is provided for selectively moving said locking device into and out of locking engagement with said plunger.

4. A hydraulic compacting press, according to claim 1, wherein said cushioning plunger has a locking projection thereon, and wherein said locking device has a locking element selectively movable into and out of locking engagement with said locking projection.

References Cited by the Examiner UNITED STATES PATENTS 1,541,358 6/25 Johnson 1816 1,851,138 3/32 Smith 18-16 2,209,404 7/40 Lassman. 2,325,687 8/43 Kux. 2,350,971 6/44 Pecker et al. 2,409,142 10/46 McCoy 1816 2,488,581 11/49 Cherry et a1. 2,509,783 5/50 Richardson 18--16.7 2,651,952 9/53 Leavenworth 1816 2,689,978 9/54 Roger 2292 2,711,561 6/55 Studli 1830 2,796,633 6/57 Carlson et a1 1816.5 3,020,589 2/62 Maritano 1816.5 3,084,387 4/63 Tochner et al 18-16 FOREIGN PATENTS 829,022 1/52 Germany.

MICHAEL V. BRINDISI, Primary Examiner. 

1. A HYDRAULIC COMPACTING PRESS FOR PRODUCING FLANGED WORKPIECES, COMPRISING A PRESS FRAME, A MAIN DIE TABLE MOUNTED FOR RECIPROCATION ON SAID PRESS FRAME, A TUBULAR DIE MOUNTED ON SAID MAIN DIE TABLE, A SECONDARY DIE TABLE CONNECTED TO SAID MAIN DIE TABLE FOR RECIPROCATION RELATIVELY THERETO, A TUBULAR FLANGE PUNCH MOUNTED ON SAID SECONDARY DIE TABLE IN TELESCOPING RELATIONSHIP WITH THE TUBULAR DIE, A BOTTOM PUNCH SUPPORT MOUNTED ON SAID PRESS FRAME, A BOTTOM PUNCH MOUNTED ON SAID BOTTOM PUNCH SUPPORT IN TELESCOPING RELATIONSHIP WITH THE FLANGE PUNCH, A HYDRAULIC MAIN DIE TABLE RECIPROCATORY MOTOR OPERATIVELY CONNECTED TO SAID MAIN DIE TABLE, A MAIN PRESSING PLATEN MOUNTED FOR RECIPROCATION ON SAID PRESS FRAME ABOVE SAID MAIN DIE TABLE, A MAIN PRESSING PUNCH MOUNTED ON SAID MAIN PRESSING PLATEN, A MAIN HYDRAULIC RECIPROCATORY PRESSING MOTOR OPERATIVELY CONNECTED TO SAID PLATEN, A HYDRAULIC RECIPROCATORY CUSHIONING MOTOR DISPOSED ADJACENT SAID SECONDARY DIE TABLE AND HAVING A RECIPROCABLE CUSHIONING PLUNGER YIELDINGLY ENGAGEABLE THEREBY IN RESPONSE TO MOTION OF SAID SECONDARY DIE TABLE TOWARD SAID CUSHIONING MOTOR DURING THE COMPACTING STROKE OF SAID MAIN PRESSING PLATEN, 